Electromagnetic driving module and lens driving device using the same

ABSTRACT

An electromagnetic driving device is provided which includes a stationary portion, an OIS driving assembly, a movable portion, and a flexible member. The stationary portion and the movable portion are arranged along a main axis. The OIS driving assembly is configured to drive the movement of the movable portion relative to the stationary portion. The flexible member extends on a plane that is located on a side of the moveable portion and connects the movable portion to the stationary portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application claims priority of Taiwan Patent Application No.105136366, filed on Nov. 9, 2016 and U.S. Provisional Patent ApplicationNo. 62/291,311, filed on Feb. 4, 2016, the entirety of which areincorporated by reference herein.

BACKGROUND

Field of the Invention

The present invention relates to a driving module and a lens drivingdevice using the same, and more particularly to an electromagneticdriving module which converts electrical energy into mechanical energy,and a lens driving device using the same.

Description of the Related Art

Some electronic devices are equipped with a driving module to drive anelement to move a predetermined distance. For example, a lens drivingdevice in a camera usually includes a driving module to generate motivepower. One or more optical lens units of the lens driving device aredriven by the motive power to move along a direction perpendicular to anoptical axis, so as to facilitate image stabilization.

However, since the driving module includes a complex driving member,such as a stepper motor, ultrasonic motor, piezoelectric actuator, etc.to generate the motive power, and the motive power has to be transmittedby a number of transmission elements, it is not easy to assemble and themanufacturing cost is high. In addition, a conventional driving moduleis also large in size and has high power consumption due to its complexconstruction.

On the other hand, in the driving module described above, a movableportion for carrying a lens is usually connected to a fixed portion by aplurality of suspension wires. The suspension wires extend in adirection that is parallel to the optical axis of the lens to facilitatethe movement of the movable portion in a direction that is perpendicularto the optical axis with respect to the fixed portion.

However, the arrangement of the suspension wires will be detrimental tothe reduction of the thickness of the driving module because the elasticcoefficient of the suspension wires in the direction that isperpendicular to the optical axis increases as its length decreases, andthe movable portion cannot be stably moved relative to the fixed portionif the length of the suspension wires is reduced.

SUMMARY

In order to address the drawbacks of the prior art, one objective of thedisclosure is to provide an electromagnetic driving module that omitsthe arrangement of the known suspension wires to reduce the thickness ofthe electromagnetic drive module.

In accordance with some embodiments of the disclosure, theelectromagnetic driving assembly includes a fixed portion, a movableportion, an OIS driving assembly and a first flexible assembly. Themovable portion is arranged in a main axis with the fixed portion. TheOIS driving assembly is configured to drive the movement of the movableportion relative to the fixed portion in a direction that isperpendicular to the main axis. The first flexible assembly ispositioned at one side of the movable portion and includes a first outerring flexible member connecting the movable portion to the fixedportion. The first outer ring flexible member extends in a plane that isperpendicular to the main axis.

In the above-mentioned embodiments, the movable portion includes a lensholder and a frame surrounding the lens holder, and the electromagneticdriving assembly further includes a focusing driving assembly configuredto drive the movement of the lens holder relative to the frame in themain axis. In addition, the first flexible assembly includes a firstinner ring flexible member connecting the lens holder to the frame.

In the above-mentioned embodiments, in the direction that isperpendicular to the main axis, the width of the first inner ringflexible member is greater than the thickness of the first inner ringflexible member. Additionally, or alternatively, in the direction ofmain axis, the width of the first outer ring flexible member is smallerthan the thickness of the first outer ring flexible member.

In the above-mentioned embodiments, the first inner ring flexible memberand the first outer ring flexible member are formed integrally.

In the above-mentioned embodiments, the first flexible assembly includesfour first inner ring flexible members separated by the same space in acircumferential direction.

In the above-mentioned embodiments, the first outer ring flexible memberincludes a plurality of bended structures.

In the above-mentioned embodiments, the electromagnetic driving assemblyfurther includes a second flexible assembly. The second flexibleassembly is positioned at the side of the movable portion that isopposite to the side where the first flexible assembly is positioned.The second flexible assembly includes a second inner ring flexiblemember connecting the lens holder to the frame and a second outer ringflexible member connecting the frame to the fixed portion.

In the above-mentioned embodiments, in the direction that isperpendicular to the main axis, the width of the second inner ringflexible member is greater than the thickness of the second inner ringflexible member. Additionally, or alternatively, in the direction of themain axis, the width of the second outer ring flexible member is lessthan the thickness of the second outer ring flexible member.

Another objective of the disclosure is to provide a lens driving deviceincluding the electromagnetic driving assembly in any one of theabove-mentioned embodiments. The lens driving device further includes alens assembly positioned on the movable portion of the electromagneticdriving assembly. The optical axis of the lens assembly is aligned withthe main axis.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the embodiments and the advantagesthereof, reference is now made to the following descriptions taken inconjunction with the accompanying drawings.

FIG. 1 shows an exploded view of an electromagnetic driving module, inaccordance with some embodiments of the disclosure.

FIG. 2 shows a top view of a first flexible assembly, in accordance withsome embodiments of the disclosure.

FIG. 3 shows a cross-sectional view taken along line A-A′ of FIG. 2.

FIG. 4 shows a top view of partial elements of an electromagneticdriving module, in accordance with some embodiments of the disclosure.

FIG. 5 shows a top view of partial elements of an electromagneticdriving module, in accordance with some embodiments of the disclosure.

FIG. 6 shows a cross-sectional view of a second flexible member, inaccordance with some embodiments of the disclosure.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

In the following detailed description, for purposes of explanation,numerous specific details and embodiments are set forth in order toprovide a thorough understanding of the present disclosure. The specificelements and configurations described in the following detaileddescription are set forth in order to clearly describe the presentdisclosure. It will be apparent, however, that the exemplary embodimentsset forth herein are used merely for the purpose of illustration, andthe inventive concept may be embodied in various forms without beinglimited to those exemplary embodiments. In addition, the drawings ofdifferent embodiments may use like and/or corresponding numerals todenote like and/or corresponding elements in order to clearly describethe present disclosure. However, the use of like and/or correspondingnumerals in the drawings of different embodiments does not suggest anycorrelation between different embodiments.

It should be noted that the elements or devices in the drawings of thepresent disclosure may be present in any form or configuration known tothose skilled in the art. In addition, the expression “an elementoverlying another element”, “an element is disposed above anotherelement”, “an element is disposed on another element” and “an element isdisposed over another element” may indicate not only that the elementdirectly contacts the other element, but also that the element does notdirectly contact the other element, there being one or more intermediateelements disposed between the element and the other element.

In this specification, relative expressions are used. For example,“lower”, “bottom”, “higher” or “top” are used to describe the positionof one element relative to another. It should be appreciated that if adevice is flipped upside down, an element at a “lower” side will becomean element at a “higher” side.

The terms “about” and “substantially” typically mean +/−20% of thestated value, more typically +/−10% of the stated value and even moretypically +/−5% of the stated value. The stated value of the presentdisclosure is an approximate value. When there is no specificdescription, the stated value includes the meaning of “about” or“substantially”.

FIG. 1 shows a schematic view of a lens driving module 1, in accordancewith some embodiments. In some embodiments, the lens driving module 1includes an electromagnetic driving module 2 and a lens assembly 3. Theelectromagnetic driving module 2 is configured to support the lensassembly 3 and to control the movement of the lens assembly 3.

In some embodiments, the electromagnetic driving module 2 includes afixed portion 10, a circuit board 14, a coil substrate 16, a movableportion 18, a first flexible assembly 22 and a second flexible assembly25. The elements of the electromagnetic driving module 2 can be added toor omitted, and the invention should not be limited by the embodiment.

In some embodiments, the fixed portion 10 includes a housing 11, a base12 and four positioning pillars 13. In some embodiments, the housing 11includes an upper housing member 111 and a lateral housing member 112.The upper housing member 111 has a rectangular shape. The lateralhousing member 112 extends from the edges of the upper housing member111 toward the base 12. The base 12 has a shape that corresponds to theshape of the upper housing member 111. The base 12 is connected to thehousing 11 via the lateral housing member 112. The four positioningpillars 13 are positioned at four corners of the base 12 and configuredfor positioning the first flexible assembly 22 and/or second flexibleassembly 25. The other elements of the electromagnetic driving module 2may be positioned in a place defined by the fixed portion 10.

The circuit board 14 is positioned on the base 12 and is configured toelectrically connect a control module (not shown in figures) to theelectric elements of the electromagnetic driving module 2. The coilsubstrate 16 is positioned on the circuit board 14 and includes a numberof OIS (optical image stabilization) driving coils, such as two OISdriving coils 162 and two OIS driving coils 164. The OIS driving coils162 and 164 are electrically connected to the circuit board 14 and areconfigured to drive the movement of the movable portion 18 in adirection that is perpendicular to the main axis M. In some embodiments,as shown in FIG. 1, the two OIS driving coils 162 are respectivelypositioned adjacent to two lateral sides of the base 12 that arearranged along the Y direction. In addition, the two OIS driving coils164 are respectively positioned adjacent to two lateral sides of thebase 12 that are arranged along the X direction.

The movable portion 18 is configured to support the lens assembly 3. Insome embodiments, the movable portion 18 includes a frame 20, a lensholder 27, a focusing driving coil 28, a number of focusing magneticelements, such as four focusing magnetic elements 30 and a number of OISmagnetic elements, such as four OIS magnetic elements 32. The elementsof the movable portion 18 can be added to or omitted, and the inventionshould not be limited by the embodiment.

The frame 20 includes four lateral frame members 201 surrounding themain axis M and connected to one another. The upper surface and/or thelower surface of each lateral frame member 201 may include a positioningplatform for facilitating the positioning of the first flexible assembly22 and the second flexible assembly 25. For example, the upper surfaceof each of the lateral frame members 201 includes a positioning platform204 for facilitating the positioning of the first flexible assembly 22.In addition, the frame 20 further includes four recesses 203. Eachrecess 203 is formed at the position where the two neighboring lateralframe members 201 are connected to each other. The relationship of thefirst flexible assembly 22 and the frame 20 is elaborated in thedescription of FIG. 2.

The lens holder 27 is surrounded by the frame 20, and the lens holder 27is penetrated by a passage 271 that extends in the main axis M. The lensassembly 3 is disposed in the passage 271. The upper surface and/or thelower surface of the lens holder 27 may include a positioning platformfor facilitating the positioning of the first flexible assembly 22 andthe second flexible assembly 25. For example, each of the upper surfaceand the lower surface of the lens holder 27 includes four positioningplatforms 273 (only four positioning platforms 273 formed on the uppersurface are shown in FIG. 3) separated by the same space in thecircumferential direction. The positioning platforms 273 on the uppersurface is configured for positioning the first flexible assembly 22,and the positioning platforms 273 on the lower surface is configured forpositioning the second flexible assembly 25. The relationships of thefirst flexible assembly 22, the second flexible assembly 25 and the lensholder 27 are elaborated in the descriptions of FIG. 2.

The focusing driving coil 28 is positioned at the outer surface of thelens holder 27 and is electrically connected to the circuit board 14 viathe first flexible assembly 22 or the second flexible assembly 25. Thefour focusing magnetic elements 30 are disposed in the recesses 203, andthe four OIS magnetic elements 32 are positioned on the bottom surfaceof the four lateral frame members 201. Being positioned by the frame 20,each of the four focusing magnetic elements 30 faces the correspondingfocusing driving coil 28, and each of the four OIS magnetic elements 32faces the corresponding OIS driving coil 162 or 164.

The four magnetic elements 30 may be magnets. One magnetic pole of eachmagnetic element 30, such as the N pole, faces the focusing driving coil28, and the other magnetic pole of each magnetic element 30, such as theS pole, faces the OIS driving coils 162 or 164. The four magneticelements 30 may be fixed on the recess 203 by any suitable method suchas gluing.

In the embodiment, a “focusing driving assembly” for driving themovement of the lens holder 27 relative to the frame 20 is composed bythe focusing driving coil 28 and the four focusing magnetic members 30.In addition, an “OIS driving assembly” for driving the movement of themovable portion 18 relative to the fixed portion is composed by the OISdriving coils 162 and 164 and the four OIS magnetic members 32.

However, it should be appreciated that while there are four focusingmagnetic members 30 and four OIS magnetic members 32, the disclosureshould not be limited thereto. In some other embodiments, the OISmagnetic members 32 are omitted, and the four focusing magnetic members30 are simultaneously positioned corresponding to the focusing drivingcoils 28 and the OIS driving coils 162 and 164.

The first flexible assembly 22 is connected to the side of the movableportion 18 that is adjacent to the upper housing member 111 and extendson a plane that is perpendicular to the main axis M. The second flexibleassembly 25 is connected to the side of the movable portion 18 that isadjacent to the base 13. The first flexible assembly 22 and the secondflexible assembly 25 may have the same configuration or differentconfigurations. In addition, the position of the first flexible assembly22 and the second flexible assembly 25 can be exchanged.

FIG. 2 shows a top view of the first flexible member 22, in accordancewith some embodiments of the disclosure. In some embodiments, the firstflexible assembly 22 includes a first outer ring flexible member 23 andone or more first inner ring flexible members 24 (such as four firstinner ring flexible member 24). The first outer ring flexible member 23has a rectangular shape and includes four sub-portions 232 and fourconnecting portions 231. The two neighboring sub-portions 232 areperpendicular to each other and connected to the each other by theconnecting portion 231. Each of the sub-portions 232 includes aconnecting portion 233 and two bended structures 234. The connectingportion 233 is arranged in the center of the sub-portion 232, and thetwo bended structures 234 are arranged at two sides of the connectingportion 233.

Each of the bended structures 234 can be made by bending a strip-shapedmaterial which has uniform width of W1 and/or a uniform thickness of T1.The width W1 is the dimension of the bended structures 234 of the firstouter ring flexible member 23 measured in a direction that isperpendicular to the main axis M. The thickness T1 is the dimension ofthe bended structures 234 of the first outer ring flexible member 23measured in a direction that is parallel to the main axis M.

The four first inner ring flexible members 24 are arranged symmetricallyto the main axis M and each includes a main section 241 and twoconnecting sections 242 and 243. The two connecting sections 242 and 243are connected to two ends of the main section 241. Each of the mainsection 241 can be made by bending a strip-shaped material which has auniform width of W2 and/or a uniform thickness of T2. The width W2 isthe dimension of the main section 241 of the first inner ring flexiblemember 24 measured in the direction that is perpendicular to the mainaxis M. The thickness T2 is the dimension of the main section 241 of thefirst inner ring flexible member 24 measured in a direction that isparallel to the main axis M.

It should be noted that while in the embodiment of FIG. 2 the firstflexible assembly 22 includes four first inner ring flexible members 24,the number of first inner ring flexible members 24 could be less orgreater according to demand. In some other embodiments, the firstflexible assembly 22 includes two first inner ring flexible members 24arranged symmetrically to the main axis M. The two first inner ringflexible members 24 has a length that is greater than that of the firstinner ring flexible member 24 shown in FIG. 2. In some otherembodiments, the first flexible assembly 22 includes only one circularfirst inner ring flexible member 24. In some other embodiments, thefirst flexible assembly 22 is omitted. In this case, the electromagneticdriving module may not be able to perform auto focusing.

The first outer ring flexible member 23 and the first inner ringflexible member 24 of the first flexible assembly 22 can be formedindependently. Alternatively, the first outer ring flexible member 23and the first inner ring flexible member 24 of the first flexibleassembly 22 are formed integrally. For example, the first outer ringflexible member 23 of the first flexible assembly 22 is connected to (oroverlapped with) the connecting sections 242 of the first inner ringflexible member 24.

FIG. 3 shows a cross-sectional view taken along line A-A′ of FIG. 2. Insome embodiments, as shown in FIG. 3, the width W1 of the first outerring flexible member 23 is less than the width W2 of the first innerring flexible member 24, and the thickness T1 of the first outer ringflexible member 23 is greater than the thickness T2 of the first innerring flexible member 24. However, the disclosure should not be limitedto this embodiment. In some embodiments, the width W1 of the first outerring flexible member 23 is less than the width W2 of the first innerring flexible member 24, and the thickness T1 of the first outer ringflexible member 23 is equal to the thickness T2 of the first inner ringflexible member 24. In some embodiments, the width W2 of the first innerring flexible member 24 is greater than the thickness T2 of the firstinner ring flexible member 24. In some embodiments, the width W1 of thefirst outer ring flexible member 23 is less than thickness T1 of thefirst outer ring flexible member 23. The advantages resulting from theabove-mentioned differences in dimensions are described later.

Referring to FIG. 1, in some embodiments, the second flexible assembly25 includes four second inner ring flexible members 26. Each of the foursecond inner ring flexible members 26 includes a main section 261 andtwo connecting sections 262 and 263. The two connecting sections 262 and263 are connected to two ends of the main sections 261.

FIG. 4 shows a top view of partial elements of the electromagneticdriving module 2, in accordance with some embodiments of the disclosure.After the assembly of the electromagnetic driving module 2, the fourconnecting portions 231 of the first outer ring flexible member 23 arefixed on the four positioning pillars 13 on the fixed portion 10, andthe four connecting portions 233 are fixed on the four positioningplatforms 204 of the movable portion 18. As a result, the movableportion 18 is connected to the fixed portion 10 via the first outer ringflexible member 23 and is able to be moved relative to the fixed portion10.

On the other hand, the four connecting sections 242 of the first innerring flexible member 24 are fixed on the four positioning platforms 204,and the four connecting portions 243 are fixed on the four positioningplatforms 273. In addition, the four connecting portions 262 of the foursecond inner ring flexible member 26 (FIG. 1) are fixed on the lowersurface of the frame 20, and the four connecting portions 264 of thesecond inner ring flexible members 26 are fixed on the lower surface ofthe lens holder 27. As a result, the lens holder 27 is connected to theframe 20 via the first inner ring flexible members 24 and the secondinner ring flexible members 26 and is able to be moved relative to theframe 20.

Referring to FIG. 1, when the electromagnetic driving module 2 is inoperation, the control module (not shown in figures) transmits electriccurrent to the OIS driving coils 162 and 164. The magnetic forceproduced between the OIS driving coils 162 and 164 and the magneticelements 30 causes the movable portion 18 to move in a direction that isperpendicular to the main axis M relative to the fixed portion 10 so asto keep the optical axis of the lens assembly 3 in alignment with themain axis M. In addition, to change the focusing position of the lensassembly, the control module (not shown in figures) transmits electriccurrent to the focusing driving coil 28. Afterwards, the lens holder 27is moved in the main axis M relative to the fixed portion 10 by themagnetic force produced between the focusing driving coils 28 and themagnetic elements 30.

During the operation of the electromagnetic driving module 2, one ormore detection assemblies (not shown in the figures) are used to detectchanges in the magnetic field of the focusing magnetic elements 30and/or the OIS magnetic elements 32 and to give feedback on the positionof the movable portion 18 and/or the lens holder 27 relative to thefixed portion 10 to the control module (not shown in the figures)according to the detected result, so as to establish a closed-loopcontrol.

In the above-mentioned embodiments, due to the width W1 of the firstouter ring flexible member 23 being less than the width W2 of the firstinner ring flexible member 24, the elastic constants of the first outerring flexible member 23 in the X-axis direction and the Y-axis directionare decreased thereby facilitating the movement of the movable portion18 relative to the fixed portion 10 in a direction that is perpendicularto the main axis M. In addition, the elastic constants of the firstinner ring flexible member 24 in the X-axis direction and the Y-axisdirection are increased, and hence the rotation of the lens holder 27 isinhibited.

On the other hand, due to the thickness T1 of the first outer ringflexible member 23 being greater than the thickness T2 of the firstinner ring flexible member 24, the elastic constant of the first outerring flexible member 23 in Z-axis direction is decreased, therebyfacilitating the movement of the lens holder 27 relative to the frame inthe main axis M.

FIG. 5 shows a top view of partial elements of an electromagneticdriving module 2 a, in accordance with some embodiments of thedisclosure. In the embodiments shown in FIG. 5, elements that aresimilar to those shown in FIG. 4 are provided with the same referencenumbers, and the features thereof are not reiterated in the interests ofbrevity. Differences between the electromagnetic driving module 2 andthe electromagnetic driving module 2 a include the frame 20 beingreplaced by a frame 20 a and the second flexible assembly 25 beingreplaced by a second flexible assembly 25 a.

In some embodiments, each of the four lateral frame members 201 of theframe 20 a includes three protrusions 205 a at the outer surface. Inaddition, the second flexible assembly 25 a includes four second innerring flexible members 26 (FIG. 1) and a second outer ring flexiblemember 29 a. The second outer ring flexible member 29 a has arectangular shape and includes four sub-portions 292 a and fourconnecting portions 291 a. The two neighboring sub-portions 292 a areperpendicular to each other and are connected to each other by theconnecting portion 291 a. Each of the sub-portions 292 a includes abended structure 293 a.

FIG. 6 shows a cross-sectional view of a second flexible assembly 25 a,in accordance with some embodiments of the disclosure. In someembodiments, each of the bended structures 293 a can be made by bendinga strip-shaped material which has a uniform width of W3 and/or a uniformthickness of T3. The width W3 is the dimension of the bended structures293 a of the second outer ring flexible member 29 a measured in adirection that is perpendicular to the main axis M. The thickness T3 isthe dimension of the bended structures 293 a of the second outer ringflexible member 29 a measured in a direction that is parallel to themain axis M.

Each of the main sections 261 can be made by bending a strip-shapedmaterial which has a uniform width of W4 and/or a uniform thickness ofT4. The width W4 is the dimension of the main section 261 of the secondinner ring flexible member 26 measured in a direction that isperpendicular to the main axis M. The thickness T4 is the dimension ofthe main section 261 of the first inner ring flexible member 26 measuredin a direction that is parallel to the main axis M.

In some embodiments, the width W3 of the second outer ring flexiblemember 29 a is less than the width W4 of the second inner ring flexiblemember 26 (FIG. 1), and the thickness T3 of the second outer ringflexible member 29 a is equal to the thickness T4 of the second innerring flexible member 26. However, the disclosure should not be limitedto this embodiment. In some embodiments, the width W3 of the secondouter ring flexible member 29 a is less than the width W4 of the secondinner ring flexible member 26, and the thickness T3 of the second outerring flexible member 29 a is greater than the thickness T4 of the secondinner ring flexible member 26. In some embodiments, the width W4 of thesecond inner ring flexible member 26 is greater than the thickness T4 ofthe second inner ring flexible member 26. In some embodiments, the widthW3 of the second outer ring flexible member 29 a is less than thethickness T3 of the second outer ring flexible member 29 a.

After the assembly of the electromagnetic driving module 2 a, the fourconnecting portions 291 a of the second outer ring flexible member 29 aare fixed on the four positioning pillars 13 on the fixed portion 10,and the four sub-portions 292 a are fixed on the protrusions 205 a ofthe movable portion 18 a. As a result, the frame 20 a of the movableportion 18 a is connected to the positioning pillars 13 of the fixedportion 10 via the first outer ring flexible member 23 and the secondouter ring flexible member 29 a and is able to be moved relative to thefixed portion 10. In the embodiment, with the arrangements of the secondflexible assembly 25 a, a large posture difference of the movableportion 18 a caused by gravity can be prevented.

Embodiments of the electromagnetic driving module in the disclosure usea flat flexible member to connect the movable portion to the fixedportion so as to facilitate the movement of the movable portion relativeto the fixed portion. Since the flexible member has a smaller elasticconstant than that of the conventional suspension wire in the directionalong which the movable portion is operated to move, the moving distanceof the movable portion is increased. Additionally, due to the omissionof the suspension wires, the thickness of the electromagnetic drivingmodule is reduced, whereby the electromagnetic driving module can beapplied to end products which are relatively thin. Moreover, with asmaller elastic constant of the flexible member, the power consumptionof the electromagnetic driving module is reduced.

Although the embodiments and their advantages have been described indetail, it should be understood that various changes, substitutions, andalterations can be made herein without departing from the spirit andscope of the embodiments as defined by the appended claims. Moreover,the scope of the present application is not intended to be limited tothe particular embodiments of the process, machine, manufacture,composition of matter, means, methods, and steps described in thespecification. As one of ordinary skill in the art will readilyappreciate from the disclosure, processes, machines, manufacture,compositions of matter, means, methods, or steps, presently existing orlater to be developed, that perform substantially the same function orachieve substantially the same result as the corresponding embodimentsdescribed herein may be utilized according to the disclosure.Accordingly, the appended claims are intended to include within theirscope such processes, machines, manufacture, compositions of matter,means, methods, or steps. In addition, each claim constitutes a separateembodiment, and the combination of various claims and embodiments arewithin the scope of the disclosure.

What is claimed is:
 1. An electromagnetic driving assembly, comprising: a fixed portion; a movable portion arranged on a main axis with the fixed portion; an OIS driving assembly configured to drive a movement of the movable portion relative to the fixed portion in a direction that is perpendicular to the main axis; and a first flexible assembly positioned at one side of the movable portion and comprising a first outer ring flexible member connecting the movable portion to the fixed portion, wherein the first outer ring flexible member extends in a plane that is perpendicular to the main axis.
 2. The electromagnetic driving assembly as claimed in claim 1, further comprising a focusing driving assembly; wherein the movable portion comprises a lens holder and a frame surrounding the lens holder, and the focusing driving assembly is configured to drive a movement of the lens holder relative to the frame in the main axis; wherein the first flexible assembly further comprises a first inner ring flexible member connecting the lens holder to the frame, and in the direction that is perpendicular to the main axis, the width of the first inner ring flexible member is greater than the thickness of the first inner ring flexible member.
 3. The electromagnetic driving assembly as claimed in claim 2, wherein the first inner ring flexible member and the first outer ring flexible member are formed integrally.
 4. The electromagnetic driving assembly as claimed in claim 2, wherein the first flexible assembly includes four first inner ring flexible members separated by the same space in a circumferential direction.
 5. The electromagnetic driving assembly as claimed in claim 1, further comprising a focusing driving assembly; wherein the movable portion comprises a lens holder and a frame surrounding the lens holder, and the focusing driving assembly is configured to drive the movement of the lens holder relative to the frame in the main axis; wherein the first flexible assembly further comprises a first inner ring flexible member connecting the lens holder to the frame, and in the direction of main axis, the width of the first outer ring flexible member is smaller than the thickness of the first outer ring flexible member.
 6. The electromagnetic driving assembly as claimed in claim 5, wherein the first inner ring flexible member and the first outer ring flexible member are formed integrally.
 7. The electromagnetic driving assembly as claimed in claim 5, wherein the first flexible assembly includes four first inner ring flexible members separated by the same space in a circumferential direction.
 8. The electromagnetic driving assembly as claimed in claim 1, wherein the first outer ring flexible member comprises a plurality of bended structures.
 9. The electromagnetic driving assembly as claimed in claim 1, further comprising: a focusing driving assembly; and a second flexible assembly positioned at a side of the movable portion that is opposite to the side where the first flexible assembly is positioned; wherein the movable portion comprises a lens holder and a frame surrounding the lens holder, and the focusing driving assembly is configured to drive the movement of the lens holder relative to the frame in the main axis, wherein the second flexible assembly comprises a second inner ring flexible member connecting the lens holder to the frame.
 10. The electromagnetic driving assembly as claimed in claim 9, wherein the second flexible assembly further comprises a second outer ring flexible member connecting the frame to the fixed portion, and in the direction that is perpendicular to the main axis, the width of the second inner ring flexible member is greater than the thickness of the second inner ring flexible member.
 11. The electromagnetic driving assembly as claimed in claim 9, wherein the second flexible assembly further comprises a second outer ring flexible member connecting the frame to the fixed portion, and in the direction of the main axis, the width of the second outer ring flexible member is less than the thickness of the second outer ring flexible member.
 12. A lens driving device, comprising: a fixed portion; a movable portion arranged on a main axis with the fixed portion; an OIS driving assembly configured to drive the movement of the movable portion relative to the fixed portion in a direction that is perpendicular to the main axis; a first flexible assembly positioned at one side of the movable portion and comprising a first outer ring flexible member connecting the movable portion to the fixed portion, wherein the first outer ring flexible member extends in a plane that is perpendicular to the main axis; and a lens assembly positioned in the movable portion, wherein the optical axis of the lens assembly is aligned with the main axis. 